Study Finds Psychiatric Disorders are Common in People with Cerebellar Degeneration

For decades, researchers have known that the cerebellum, a fist-sized structure at the back of the brain, helps to coordinate the body and to fine-tune movements. A growing body of research conducted during the last decade supports the notion that the cerebellum also plays a role in cognition, emotion, and other non-motor symptoms.

Now, a new study shows that most patients with movement disorders caused by damage to the cerebellum also have psychiatric symptoms. The study suggests that patients with cerebellar diseases may benefit from screening and treatment of psychiatric symptoms.

"It is not widely recognized that patients with cerebellar diseases have these psychiatric disorders," says senior author Russell Margolis, M.D., of Johns Hopkins University School of Medicine in Baltimore, Maryland. "Our goal was to test what clinicians have already observed in these patients." The study was published in the August 2002 issue of the American Journal of Psychiatry.

Cerebellar disorders usually strike adults in middle age. While spinocerebellar ataxia and other such diseases are hereditary, tumors, stroke, and other non-hereditary conditions also affect the cerebellum. While the symptoms of cerebellar disorders vary, they typically include clumsiness of the arms and legs, trouble with balance and walking, and difficulty with speech and sometimes swallowing.

Previous studies and case reports have suggested that people with cerebellar disorders sometimes develop personality changes and other psychiatric problems. However, this is the first study to compare symptoms in patients with cerebellar disorders to those of patients with a movement disorder not related to the cerebellum (Huntington's disease). Huntington's disease results from loss of cells in a brain region called the basal ganglia.

In the study, Margolis and his colleagues used psychiatric evaluations and psychopathology ratings to diagnose psychiatric disorders in 31 patients with degenerative cerebellar diseases, 21 patients with Huntington's disease, and 29 people who had no signs of brain disease but who had lived with the patients (usually spouses).

The researchers also used standard rating scales to assess the severity of cerebellar damage and neurological symptoms in these three groups. The researchers chose to test people with close relationships to the patients - rather than other healthy people - because they were likely to share some of the psychological and social stresses that affected the patients in this study. This helped to distinguish psychiatric problems that result from the disease itself from psychological reactions to the stress associated with the disease.

Seventy-seven percent of patients with cerebellar diseases had psychiatric disorders, which is nearly twice the rate of psychiatric disorders in people without neurological disorders (41 percent), the researchers found. Psychiatric disorders diagnosed in the study included mood and psychotic disorders, anxiety disorders and personality changes.

From a clinical standpoint, the study suggests that patients with movement disorders should be screened for psychiatric symptoms. Dr. Margolis says diagnosis and treatment of such symptoms can vastly improve quality of life for patients and their families. "The high rate of psychiatric disorders in these patients suggests that many, if not most, can benefit from treatment, even if the course of the brain disease itself cannot be reversed," he adds. "Many symptoms can be eased, and we can help families better understand patients' cognitive and emotional limitations."

The study is a major milestone from a research perspective as well, providing new impetus for scientists to learn more about the cerebellum.

"The results of this study suggest that the cerebellum has an important role in cognition and emotion," says study author Christopher A. Ross, M.D., Ph.D., also of Johns Hopkins Hospital in Baltimore. "Now, we need to develop a better understanding of specific regions of the cerebellum and of the cellular and molecular mechanisms of cerebellar diseases."